Electro-mechanical surgical device

ABSTRACT

An electromechanical surgical device includes: a housing; an elongated shaft extending from the housing, a distal end of the elongated shaft being detachably coupleable to a surgical instrument; at least two axially rotatable drive shafts disposed within the elongated shaft, a distal end of each of the drive shafts being configured to couple with the surgical instrument; a steering cable arrangement, the steering cable arrangement being configured to steer the distal end of the elongated shaft; and a motor system disposed within the housing, the motor system being configured to drive the drive shafts and the steering cable arrangement. A control system may be provided for controlling the motor system. A remote control unit may also be provided for controlling the motor system via the control system. Sensors, such as optical or Hall-effect devices, may be provided for determining the position of the elements of the surgical instrument based on the detected rotation of the drive shafts. A memory unit stores a plurality of operating programs or algorithms, each corresponding to a type of surgical instrument attachable to the electro-mechanical surgical device. The control system reads or selects from the plurality of operating programs or algorithms, the operating program or algorithm corresponding to the type of surgical instrument attached to the electromechanical surgical device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 10/256,681, filed onSep. 26, 2002, now U.S. Pat. No. 6,849,071, which is a division of U.S.application Ser. No. 09/723,715, filed on Nov. 28, 2000, now U.S. Pat.No. 6,793,652, which is a continuation-in-part of U.S. application Ser.No. 09/324,451, filed on Jun. 2, 1999, now U.S. Pat. No. 6,315,184, acontinuation-in-part of U.S. application Ser. No. 09/324,452, filed onJun. 2, 1999, now U.S. Pat. No. 6,443,973, a continuation-in-part ofU.S. application Ser. No. 09/351,534, filed on Jul. 12, 1999, now U.S.Pat. No. 6,264,087, a continuation-in-part of U.S. application Ser. No.09/510,923, filed on Feb. 22, 2000, now U.S. Pat. No. 6,517,565, whichis a continuation-in-part of U.S. application Ser. No. 09/324,452 filedon Jun. 2, 1999, now U.S. Pat. No. 6,443,973, a continuation-in-part ofU.S. application Ser. No. 09/510,927, filed on Feb. 22, 2000, now U.S.Pat. No. 6,716,233, which is a continuation-in-part of U.S. applicationSer. No. 09/324,452 filed on Jun. 2, 1999, now U.S. Pat. No. 6,443,973,and a continuation-in-part of U.S. application Ser. No. 09/510,932,filed on Feb. 22, 2000, now U.S. Pat. No. 6,491,201.

FIELD OF THE INVENTION

The present invention relates to an electromechanical surgical device.

BACKGROUND INFORMATION

The literature is replete with descriptions of surgical devices. Forexample, U.S. Pat. No. 4,705,038 to Sjostrom et al. describes a surgicalsystem for powered instruments. The system includes a handpiececontaining a motor and including a recess adapted to receive one of aplurality of surgical devices. A pair of reed switches is disposedwithin the recess, and each of the surgical devices includes one or twomagnets adapted to actuate the reed switches in a particular combinationwhen the device is assembled with the handpiece. The combination of reedswitches activated by the magnets of the assembled handpiece andsurgical device identifies to the system the surgical device soassembled with the handpiece. The number of possible surgical devicesidentifiable by this system is limited to the four possible combinationof up to two magnets.

U.S. Pat. No. 4,995,877 to Ams et al. describes a device with arotationally-driven surgical instrument. The device includes a hand-heldelement containing a driving motor for driving a tool insert. The devicefurther includes a control unit having a storage unit for storingoperational data manually set by the user of the device. Such data maybe transferred to a code carrier, which is insertable into a plug-infacility.

U.S. Pat. No. 5,249,583 to Mallaby describes an electronic biopsyinstrument with wiperless position sensors. A slotted disc and a cam areaffixed to a drive shaft, which is driven by a motor. A pair of sensorsis arranged so that each sensor is activated when the slot of theslotted disc is positioned over the sensor to thereby determine theposition of a cannula and a stylet of the instrument. The sensors,slotted disc, cam, motor and rechargeable batteries for powering theinstrument are contained within a housing of the instrument.

U.S. Pat. No. 5,383,880 to Hooven describes an endoscopic surgicalsystem with sensing means. The instrument includes a motor disposedwithin a hand-held housing. A sensor is provided in the head of aninstrument of the system for sensing the blood oxygen content ofadjacent tissue.

Similarly, U.S. Pat. No. 5,395,033 to Byme et al. describes anendoscopic surgical instrument having a pair of jaws. A permanent magnetis disposed in a distal end of one of the jaws, and a magneto-resistivesensor is disposed in a distal end of the other one of the jaws. Themagnet produces a magnetic field between the jaws, and the sensormeasures the variations in the magnetic field so that the distancebetween the jaws may be determined.

U.S. Pat. No. 5,467,911 to Tsuruta et al. describes a surgical devicefor stapling and fastening body tissues. The device includes anoperation section and an insertion section, which is detachablyattachable to the operation section.

U.S. Pat. Nos. 5,518,163, 5,518,164 and 5,667,517, all to Hooven,describe an endoscopic surgical system, which includes a motor disposedin a handle portion. A sensing member, which is used to sense the bloodoxygen content of adjacent tissue, is disposed in a head of theinstrument. A contact is also provided in the head of the instrument.When a firing nut of the system has moved forward in the head to driveand form surgical staples disposed therein, the firing nut engages thecontact, thereby reversing the motor to retract the firing nut.

U.S. Pat. No. 5,653,374 to Young et al., U.S. Pat. No. 5,779,130 toAlesi et al. and U.S. Pat. No. 5,954,259 to Viola et al. describe aself-contained powered surgical apparatus, which includes a motorassembly and power source disposed within a hand-held instrument body.

These instruments and systems described above suffer numerousdisadvantages. For example, in several of the above-describedinstruments and systems, a motor is disposed within a handle of theinstrument. Due to size considerations, these motors generally providelimited torque. In certain of the instruments and systems describedabove, a battery is provided within the handle for powering the motor.Such battery systems, however, provide limited electrical power to themotors, further limiting the torque output by the motors.

In addition, it is generally not possible to accurately ascertain thepositions of the operative elements of the aforementioned instrumentsand systems.

A further disadvantage of the above-described instruments and systems isthat such instruments and systems typically require manual manipulationand operation. When a motor is provided in the handle of suchinstruments, manual manipulation and operation is awkward and cumbersometo the operator.

It is therefore an object of the present invention to provide anelectro-mechanical surgical device, in which a motor system is providedremote from the surgical instrument.

It is a further object of the present invention to provide anelectromechanical surgical device, which is operable via a remotecontrol unit.

It is another object of the present invention to provide anelectromechanical surgical device, in which the relative position of thecomponents thereof may be accurately determined.

It is still another object of the present invention to provide anelectro-mechanical surgical device, which includes a plurality ofoperating programs or algorithms. Each operating program or algorithmcorresponds to a respective surgical instrument or attachment attachableto the electromechanical surgical device.

SUMMARY

The above and other beneficial objects and advantages of the presentinvention are most effectively attained by providing anelectromechanical surgical device as described herein. In one exampleembodiment, an electromechanical surgical device includes: a housing; anelongated shaft extending from the housing, a distal end of theelongated shaft being detachably coupleable to a surgical instrument; atleast two axially rotatable drive shafts disposed within the elongatedshaft, a distal end of each of the drive shafts being configured tocouple with the surgical instrument; a steering cable arrangement beingconfigured to steer the distal end of the elongated shaft; and a motorsystem disposed within the housing and configured to drive the driveshafts and the steering cable arrangement.

In another example embodiment, the electromechanical surgical deviceincludes a control system and a remote control unit configured tocommunicate with the control system to control the motor system via thecontrol system. The remote control unit may include a wired remotecontrol unit and/or a wireless remote control unit.

In yet another example embodiment, the electromechanical surgical deviceincludes a sensor configured to detect the rotation of the drive shaft.The control system is configured to determine a position of the elementsof the surgical instrument based on the detected rotation of the driveshaft.

In still another example embodiment, the electromechanical surgicaldevice includes a first memory unit configured to store a plurality ofoperating programs or algorithms, each corresponding to a respectivetype of surgical instrument. The control system is configured to detectthe type of surgical instrument attached to the electromechanicalsurgical device and to select or read the operating program or algorithmcorresponding to the attached surgical instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electromechanical surgical deviceaccording to the present invention;

FIG. 2 is a side elevational view, partially in section, of a flexibleshaft of the electromechanical surgical device illustrated in FIG. 1;

FIG. 3 is a cross-sectional view of the flexible shaft taken along theline 3-3 shown in FIG. 2;

FIG. 4 is a rear end view of a first coupling of the flexible shaftillustrated in FIG. 2;

FIG. 5 is a front end view of a second coupling of the flexible shaftillustrated in FIG. 2;

FIG. 6 is a schematic view illustrating a motor arrangement of theelectro-mechanical surgical device illustrated in FIG. 1;

FIG. 7 is a schematic view of the electromechanical surgical deviceillustrated in FIG. 1;

FIG. 8 is a schematic view of an encoder of the flexible shaftillustrated in FIGS. 2 and 3;

FIG. 9 is a schematic cross-sectional side view of an exemplary circularsurgical stapler attachment used in connection with theelectromechanical surgical device illustrated in FIG. 1;

FIG. 10 is a schematic view of a memory device of the exemplary circularsurgical stapler attachment illustrated in FIG. 9;

FIG. 11 is a schematic view of a wireless remote control unit of theelectro-mechanical surgical device illustrated in FIG. 1;

FIG. 12 is a schematic view of a wired remote control unit of theelectro-mechanical surgical device illustrated in FIG. 1;

FIG. 13 illustrates a flowchart of a main operating program foroperating the electromechanical surgical device illustrated in FIG. 1;

FIGS. 14 a-14 d illustrate a flowchart of a fire routine for a circularsurgical stapler attachment, such as that illustrated in FIG. 9;

FIGS. 15 a and 15 b illustrate a flowchart of a clamp routine for acircular surgical stapler attachment, such as that illustrated in FIG.9; and

FIG. 16 illustrates a flowchart of an unclamp routine for a circularsurgical stapler attachment, such as that illustrated in FIG. 9.

DETAILED DESCRIPTION

Those skilled in the art will gain an appreciation of the presentinvention from a reading of the following description when viewed inconjunction with the accompanying drawings of FIGS. 1-16, inclusive. Theindividual reference characters designate the same or similar elementsthroughout the several views.

Referring to FIG. 1, there is seen a perspective view of anelectro-mechanical surgical device 10 according to an example embodimentof the present invention. Electro-mechanical surgical device 10 mayinclude, for example, a remote power console 12, which includes ahousing 14 having a front panel 15. Mounted on front panel 15 are adisplay device 16 and indicators 18 a, 18 b, which are more fullydescribed hereinbelow. A flexible shaft 20 may extend from housing 14and may be detachably secured thereto via a first coupling 22. Thedistal end 24 of flexible shaft 20 may include a second coupling 26adapted to detachably secure a surgical instrument or attachment to thedistal end 24 of flexible shaft 20. The surgical instrument orattachment may be, for example, a surgical stapler, a surgical cutter, asurgical stapler-cutter, a linear surgical stapler, a linear surgicalstapler-cutter, a circular surgical stapler, a circular surgicalstapler-cutter, a surgical clip applier, a surgical clip ligator, asurgical clamping device, a vessel expanding device, a lumen expandingdevice, a scalpel, a fluid delivery device or any other type of surgicalinstrument. Such surgical instruments are described, for example, inU.S. patent application Ser. No. 09/324,451, entitled “A Stapling Devicefor Use with an Electromechanical Driver Device for Use withAnastomosing, Stapling, and Resecting Instruments,” U.S. patentapplication Ser. No. 09/324,452, entitled “Electromechanical DriverDevice for Use with Anastomosing, Stapling, and Resecting Instruments,”U.S. patent application Ser. No. 09/351,534, entitled “AutomatedSurgical Stapling System,” U.S. patent application Ser. No. 09/510,926,entitled “A Vessel and Lumen Expander Attachment for Use with anElectromechanical Driver Device,” U.S. patent application Ser. No.09/510,927, entitled “Electromechanical Driver and Remote SurgicalInstruments Attachment Having Computer Assisted Control Capabilities,”U.S. patent application Ser. No. 09/510,931, entitled “A Tissue StaplingAttachment for Use with an Electromechanical Driver Device,” U.S. patentapplication Ser. No. 09/510,932, entitled “A Fluid Delivery Mechanismfor Use with Anastomosing, Stapling, and Resecting Instruments,” andU.S. patent application Ser. No. 09/510,933, entitled “A Fluid DeliveryDevice for Use with Anastomosing, Stapling, and Resecting Instruments,”each of which is expressly incorporated herein in its entirety byreference thereto.

Referring to FIG. 2, there is seen a side view, partially in section, offlexible shaft 20. According to one embodiment, flexible shaft 20includes a tubular sheath 28, which may include a coating or othersealing arrangement to provide a fluid-tight seal between the interiorchannel 40 thereof and the environment. Sheath 28 may be formed of atissue-compatible, sterilizable elastomeric material. The sheath 28 mayalso be formed of a material that is autoclavable. Disposed within theinterior channel 40 of flexible shaft 20, and extending along the entirelength thereof, may be a first rotatable drive shaft 30, a secondrotatable drive shaft 32, a first steering cable 34, a second steeringcable 35, a third steering cable 36, a fourth steering cable 37 and adata transfer cable 38. FIG. 3 is a cross-sectional view of flexibleshaft 20 taken along the line 3-3 shown in FIG. 2 and furtherillustrates the several cables 30, 32, 34, 35, 36, 37, 38. Each distalend of the steering cables 34, 35, 36, 37 is affixed to the distal end24 of the flexible shaft 20. Each of the several cables 30, 32, 34, 35,36, 37, 38 may be contained within a respective sheath.

Referring now to FIG. 4, there is seen a rear end view of first coupling22. First coupling 22 includes a first connector 44, a second connector48, a third connector 52 and a fourth connector 56, each rotatablysecured to first coupling 22. Each of the connectors 44, 48, 52, 56includes a respective recess 46, 50, 54, 58. As shown in FIG. 4, eachrecess 46, 50, 54, 58 may be hexagonally shaped. It should beappreciated, however, that the recesses 46, 50, 54, 58 may have anyshape and configuration to non-rotatably couple and rigidly attach theconnectors 44, 48, 52, 56 to respective drive shafts of the motorarrangement contained within the housing 12, as more fully describedbelow. It should be appreciated that complementary projections may beprovided on respective drive shafts of the motor arrangement to therebydrive the drive elements of the flexible shaft 20 as described below. Itshould also be appreciated that the recesses may be provided on thedrive shafts and complementary projections may be provided on theconnectors 44, 48, 52, 56. Any other coupling arrangement configured tonon-rotatably and releasably couple the connectors 44, 48, 52, 56 andthe drive shafts of the motor arrangement may be provided.

One of the connectors 44, 48, 52, 56 is non-rotatably secured to thefirst drive shaft 30, and another one of the connectors 44, 48, 52, 56is non-rotatably secured to the second drive shaft 32. The remaining twoof the connectors 44, 48, 52, 56 engage with transmission elementsconfigured to apply tensile forces on the steering cables 34, 35, 36, 37to thereby steer the distal end 24 of the flexible shaft 20. The datatransfer cable 38 is electrically and logically connected with dataconnector 60. Data connector 60 includes, for example, electricalcontacts 62, corresponding to and equal in number to the number ofindividual wires contained in the data cable 38. First coupling 22includes a key structure 42 to properly orient the first coupling 22 toa mating and complementary coupling arrangement disposed on the housing12. Such key structure 42 may be provided on either one, or both, of thefirst coupling 22 and the mating and complementary coupling arrangementdisposed on the housing 12. First coupling 22 may include aquick-connect type connector, which may use, for example, a simplepushing motion to engage the first coupling 22 to the housing 12. Sealsmay be provided in conjunction with any of the several connectors 44,48, 52, 56, 60 to provide a fluid-tight seal between the interior offirst coupling 22 and the environment.

Referring now to FIG. 5, there is seen a front end view of the secondcoupling 26 of flexible shaft 20. Second coupling 26 includes a firstconnector 66 and a second connector 68, each being rotatably secured tothe second coupling 26 and each being non-rotatably secured to a distalend of a respective one of the first and second drive shafts 30, 32. Aquick-connect type fitting 64 is provided on the second coupling 26 fordetachably securing the surgical instrument or attachment thereto. Thequick-connect type fitting 64 may be, for example, a rotaryquick-connect type fitting, a bayonet type fitting, etc. A key structure74 is provided on the second coupling 26 for properly aligning thesurgical instrument or attachment to the second coupling 26. The keystructure or other arrangement for properly aligning the surgicalinstrument or attachment to the flexible shaft 20 may be provided oneither one, or both, of the second coupling 26 and the surgicalinstrument or attachment. In addition, the quick-connect type fittingmay be provided on the surgical instrument or attachment. A dataconnector 70, having electrical contacts 72, is also provided in thesecond coupling 26. Like the data connector 60 of first coupling 22, thedata connector 70 of second coupling 26 includes contacts 72electrically and logically connected to the respective wires of datatransfer cable 38 and contacts 62 of data connector 60. Seals may beprovided in conjunction with the connectors 66, 68, 70 to provide afluid-tight seal between the interior of second coupling 26 and theenvironment.

Disposed within housing 14 of the remote power console 12 areelectro-mechanical driver elements configured to drive the drive shafts30, 32 and the steering cables 34, 35, 36, 37 to thereby operate theelectromechanical surgical device 10 and the surgical instrument orattachment attached to the second coupling 26. In the example embodimentillustrated schematically in FIG. 6, five electric motors 76, 80, 84,90, 96, each operating via a power source, may be disposed in the remotepower console 12. It should be appreciated, however, that anyappropriate number of motors may be provided, and the motors may operatevia battery power, line current, a DC power supply, an electronicallycontrolled DC power supply, etc. It should also be appreciated that themotors may be connected to a DC power supply, which is in turn connectedto line current and which supplies the operating current to the motors.

FIG. 6 illustrates schematically one possible arrangement of motors. Anoutput shaft 78 of a first motor 76 engages with the first connector 44of the first coupling 22 when the first coupling 22, and, therefore,flexible shaft 20, is engaged with the housing 14 to thereby drive thefirst drive shaft 30 and first connector 66 of second coupling 26.Similarly, an output shaft 82 of a second motor 80 engages the secondconnector 48 of first coupling 22 when first coupling 22, and,therefore, flexible shaft 20 is engaged with the housing 14 to therebydrive the second drive shaft 32 and second connector 68 of secondcoupling 26. An output shaft 86 of a third motor 84 engages the thirdconnector 52 of the first coupling 22 when the first coupling 22, and,therefore, flexible shaft 20, is engaged with the housing 14 to therebydrive the first and second steering cables 34, 35 via a first pulleyarrangement 88. An output shaft 92 of a fourth motor 90 engages thefourth connector 56 of the first coupling 22 when the first coupling 22,and, therefore, flexible shaft 20, is engaged with the housing 14 tothereby drive the third and fourth steering cables 36, 37 via a secondpulley arrangement 94. The third and fourth motors 84, 90 may be securedon a carriage 100, which is selectively movable via an output shaft 98of a fifth motor 96 between a first position and a second position toselectively engage and disengage the third and fourth motors 84, 90 withthe respective pulley arrangement 88, 94 to thereby permit the flexibleshaft 20 to become taut and steerable or limp as necessary. It should beappreciated that other mechanical, electrical or electromechanicalmechanisms may be used to selectively engage and disengage the steeringmechanism. The motors may be arranged and configured as described, forexample, in U.S. patent application Ser. No. 09/510,923, entitled “ACarriage Assembly for Controlling a Steering Wire Mechanism Within aFlexible Shaft,” which is expressly incorporated herein in its entiretyby reference thereto.

Referring now to FIG. 7, there is seen a schematic view of theelectro-mechanical surgical device 10. A controller 122 is provided inthe housing 14 of remote power console 12 and is configured to controlall functions and operations of the electromechanical surgical device 10and any surgical instrument or attachment attached to the flexible shaft20. A memory unit 130 is provided and may include memory devices, suchas, a ROM component 132 and/or a RAM component 134. ROM component 132 isin electrical and logical communication with controller 122 via line136, and RAM component 134 is in electrical and logical communicationwith controller 122 via line 138. RAM component 134 may include any typeof random-access memory, such as, for example, a magnetic memory device,an optical memory device, a magneto-optical memory device, an electronicmemory device, etc. Similarly, ROM component 132 may include any type ofread-only memory, such as, for example, a removable memory device, suchas a PC-Card or PCMCIA-type device. It should be appreciated that ROMcomponent 132 and RAM component 134 may be embodied as a single unit ormay be separate units and that ROM component 132 and/or RAM component134 may be provided in the form of a PC-Card or PCMCIA-type device.Controller 122 is further connected to front panel 15 of housing 14 and,more particularly, to display device 16 via line 154 and indicators 18a, 18 b via respective lines 156, 158. Lines 116, 118, 124, 126, 128electrically and logically connect controller 122 to first, second,third, fourth and fifth motors 76, 80, 84, 90, 96, respectively. A wiredremote control unit (“RCU”) 150 is electrically and logically connectedto controller 122 via line 152. A wireless RCU 148 is also provided andcommunicates via a wireless link 160 with a receiving/sending unit 146connected via line 144 to a transceiver 140. The transceiver 140 iselectrically and logically connected to controller 122 via line 142.Wireless link 160 may be, for example, an optical link, such as aninfrared link, a radio link or any other form of wireless communicationlink.

A switch device 186, which may be, for example, an array of DIPswitches, may be connected to controller 122 via line 188. Switch device186 may be used, for example, to select one of a plurality of languagesused in displaying messages and prompts on the display device 16. Themessages and prompts may relate to, for example, the operation and/orthe status of the electromechanical surgical device 10 and/or to anysurgical instrument or attachment attached thereto.

According to the example embodiment of the present invention, a firstencoder 106 is provided within the second coupling 26 and is configuredto output a signal in response to and in accordance with the rotation ofthe first drive shaft 30. A second encoder 108 is also provided withinthe second coupling 26 and is configured to output a signal in responseto and in accordance with the rotation of the second drive shaft 32. Thesignal output by each of the encoders 106, 108 may represent therotational position of the respective drive shaft 30, 32 as well as therotational direction thereof. Such encoders 106, 108 may be, forexample, Hall-effect devices, optical devices, etc. Although theencoders 106, 108 are described as being disposed within the secondcoupling 26, it should be appreciated that the encoders 106, 108 may beprovided at any location between the motor system and the surgicalinstrument or attachment.

FIG. 8 is a schematic view of an encoder 106, 108, which includes aHall-effect device. Mounted non-rotatably on drive shaft 30, 32 is amagnet 240 having a north pole 242 and a south pole 244. The encoder106, 108 further includes a first sensor 246 and second sensor 248,which are disposed approximately 90° apart relative to the longitudinal,or rotational, axis of drive shaft 30, 32. The output of the sensors246, 248 is persistent and changes its state as a function of a changeof polarity of the magnetic field in the detection range of the sensor.Thus, based on the output signal from the encoders 106, 108, the angularposition of the drive shaft 30, 32 may be determined within one-quarterrevolution and the direction of rotation of the drive shaft 30, 32 maybe determined. The output of each encoder 106, 108 is transmitted via arespective line 110, 112 of data transfer cable 38 to controller 122.The controller 122, by tracking the angular position and rotationaldirection of the drive shafts 30, 32 based on the output signal from theencoders 106, 108, can thereby determine the position and/or state ofthe components of the surgical instrument or attachment connected to theelectromechanical surgical device 10. That is, by counting therevolutions of the drive shaft 30, 32, the controller 122 can determinethe position and/or state of the components of the surgical instrumentor attachment connected to the electromechanical surgical device 10.

For example, in a circular surgical stapler attachment 250, such as thatshown schematically in cross-section in FIG. 9, the circular surgicalstapler attachment 250 includes a coupling 260 adapted by size andconfiguration to cooperate with the second coupling 26 of flexible shaft20 to detachably attach the circular surgical stapler attachment 250thereto. Circular surgical stapler attachment 250 includes an anvilportion 254 having an anvil 256 mounted on the distal end of an anvilstem 258. The anvil stem 258 is extended and retracted by the operationof an anvil drive shaft 262, which is rotatably secured within the bodyportion 252 of the circular surgical stapler attachment 250. A proximalend of the anvil drive shaft 262 includes a first connector 268 adaptedby size and configuration to couple with the first connector 66 ofsecond coupling 26. Circular surgical stapler attachment 250 furtherincludes a staple driver/cutter 264 driven by the rotation of a stapledriver/cutter drive shaft 266. The proximal end of the stapledriver/cutter drive shaft 266 includes a second connector 270, which isadapted by size and configuration to couple with the second connector 68of second coupling 26. Thus, in the example circular surgical staplerattachment 250 shown in FIG. 9, the extension and retraction of theanvil 256 is effected by the operation of the first motor 76, and theextension and retraction of the staple driver/cutter 264 is effected bythe operation of the second motor 80. The pitch of the anvil drive shaft262 and the pitch of the stapler driver/cutter drive shaft 266 arepredetermined and known quantities. That is, the advancement distance ofthe anvil 256 and the staple driver/cutter 264 are functions of, andascertainable on the basis of, the rotation of the respective driveshaft 30, 32. By ascertaining an absolute position of the anvil 256 andthe staple driver/cutter 264 at a point in time, the relativedisplacement of the anvil 256 and staple driver/cutter 264, based on theoutput signal from the encoders 106, 108 and the known pitches of theanvil drive shaft 262 and staple driver/cutter drive shaft 266, may beused to ascertain the absolute position of the anvil 256 and stapledriver/cutter 264 at all times thereafter. The absolute position of theanvil 256 and staple driver/cutter 264 may be fixed and ascertained atthe time that the circular surgical stapler attachment 250 is firstcoupled to the flexible shaft 20. Alternatively, the position of theanvil 256 and the staple driver/cutter 264 relative to, for example, thebody portion 252 may be determined based on the output signal from theencoders 106, 108.

Circular surgical stapler attachment 250 further includes a dataconnector 272 adapted by size and configuration to electrically andlogically connect to connector 70 of second coupling 26. In the exampleembodiment, data connector 272 includes contacts (not shown) equal innumber to the number of leads 72 of connector 70. Contained within thecircular surgical stapler attachment 250 is a memory unit 174electrically and logically connected with the data connector 272. Memoryunit 174 may be in the form of, for example, an EEPROM, EPROM, etc. andmay be contained, for example, within the body portion 252 of circularsurgical stapler attachment 250.

FIG. 10 schematically illustrates the memory unit 174. As seen in FIG.10, data connector 272 includes contacts 276, each electrically andlogically connected to memory unit 174 via a respective line 278. Memoryunit 174 is configured to store, for example, a serial number data 180,an attachment type identifier (ID) data 182 and a usage data 184. Memoryunit 174 may additionally store other data. Both the serial number data180 and the ID data 182 may be configured as read-only data. In theexample embodiment, serial number data 180 is data uniquely identifyingthe particular surgical instrument or attachment, whereas the ID data182 is data identifying the type of the attachment, such as, forexample, a circular surgical stapler attachment, a linear surgicalstapler attachment, etc. The usage data 184 represents usage of theparticular attachment, such as, for example, the number of times theanvil 256 of the circular surgical stapler attachment 250 has beenadvanced or the number of times that the staple driver/cutter 264 of thecircular surgical stapler attachment 250 has been advanced or fired.

It should be appreciated that each types of surgical instrument orattachment attachable to the distal end 24 of the flexible shaft 20 maybe designed and configured to be used a single time or multiple times.The surgical instrument or attachment may also be designed andconfigured to be used a predetermined number of times. Accordingly, theusage data 184 may be used to determine whether the surgical instrumentor attachment has been used and whether the number of uses has exceededthe maximum number of permitted uses. As more fully described below, anattempt to use a surgical instrument or attachment after the maximumnumber of permitted uses has been reached will generate an ERRORcondition.

It should be appreciated that the circular surgical stapler attachment250 illustrated in FIG. 9 is intended to be merely an example of asurgical attachment used in conjunction with the electro-mechanicalsurgical device 10. It should be further appreciated that any other typeof surgical instrument or attachment, such as those enumeratedhereinabove, may be used in conjunction with the electro-mechanicalsurgical device 10. Regardless of the particular type of surgicalinstrument or attachment, in the example embodiment of the presentinvention, the surgical instrument or attachment includes the couplingelements 268, 270, 272, as necessary for proper operation of thesurgical instrument or attachment, as well as the memory unit 174.Although the drive shafts and motors are described herein as effectingparticular functions of the circular surgical stapler attachment 250, itshould be appreciated that the drive shafts and motors may effect thesame or other functions of other types of surgical instruments orattachments.

Referring again to FIG. 7, in accordance with the example embodiment ofthe present invention, the controller 122 is configured to read the IDdata 182 from the memory unit 174 of the surgical instrument orattachment when the surgical instrument or attachment is initiallyconnected to the flexible shaft 20. The memory unit 174 is electricallyand logically connected to the controller 122 via line 120 of datatransfer cable 38. Based on the read ID data 182, the controller 122 isconfigured to read or select from the memory unit 130, an operatingprogram or algorithm corresponding to the type of surgical instrument orattachment connected to the flexible shaft 20. The memory unit 130 isconfigured to store the operating programs or algorithms for eachavailable type of surgical instrument or attachment, the controller 122selecting and/or reading the operating program or algorithm from thememory unit 130 in accordance with the ID data 182 read from the memoryunit 174 of an attached surgical instrument or attachment. As indicatedabove, the memory unit 130 may include a removable ROM component 132and/or RAM component 134. Thus, the operating programs or algorithmsstored in the memory unit 130 may be updated, added, deleted, improvedor otherwise revised as necessary. It should be appreciated that theserial number data 180 and/or usage data 184 may also be used todetermine which of a plurality of operating programs or algorithms isread or selected from the memory unit 130. It should also be appreciatedthat the operating program or algorithm may alternatively be stored inthe memory unit 174 of the surgical instrument or attachment andtransferred to the controller 122 via the data transfer cable 38. Oncethe appropriate operating program or algorithm is read or selected by,or transmitted to, the controller 122, the controller 122 causes theoperating program or algorithm to be executed in accordance withoperations performed by the user via the wired RCU 150 and/or thewireless RCU 148. As indicated hereinabove, the controller 122 iselectrically and logically connected with the first, second, third,fourth and fifth motors 76, 80, 84, 90, 96 via respective lines 116,118, 124, 126, 128 and controls such motors 76, 80, 84, 90, 96 inaccordance with the read, selected or transmitted operating program oralgorithm via the respective lines 116, 118, 124, 126, 128.

Referring now to FIG. 11, there is seen a schematic view of wireless RCU148. Wireless 148 includes a steering controller 300 having a pluralityof switches 302, 304, 306, 308 arranged under a four-way rocker 310. Theoperation of switches 302, 304, via rocker 310, controls the operationof first and second steering cables 34, 35 via third motor 84.Similarly, the operation of switches 306, 308, via rocker 310, controlsthe operation of third and fourth steering cables 36, 37 via fourthmotor 92. It should be appreciated that rocker 310 and switches 302,304, 306, 308 are arranged so that the operation of switches 302, 304steers the flexible shaft 20 in the north-south direction and that theoperation of switches 306, 308 steers the flexible shaft 20 in theeast-west direction. Reference herein to north, south, east and west ismade to a relative coordinate system. Alternatively, a digital joystick,analog joystick, etc. may be provided in place of rocker 310 andswitches 302, 304, 306, 308. Potentiometers or any other type ofactuator may also be used in place of switches 302, 304, 306, 308.

Wireless RCU 148 further includes a steering engage/disengage switch312, the operation of which controls the operation of fifth motor 96 toselectively engage and disengage the steering mechanism. Wireless RCU148 also includes a two-way rocker 314 having first and second switches316, 318 operable thereby. The operation of these switches 316, 318controls certain functions of the electro-mechanical surgical device 10and any surgical instrument or attachment attached to the flexible shaft20 in accordance with the operating program or algorithm correspondingto the attached surgical instrument or attachment, if any. For example,where the surgical instrument is a circular surgical stapler attachment250, such as that shown in FIG. 9 and described hereinabove, operationof the two-way rocker 314 may control the advancement and retraction ofthe anvil 256. Wireless RCU 148 is provided with yet another switch 320,the operation of which may further control the operation of theelectromechanical surgical device 10 and any surgical instrument orattachment attached to the flexible shaft 20 in accordance with theoperating program or algorithm corresponding to the attached surgicalinstrument or attachment, if any. For example, when the circularsurgical stapler attachment 250 is attached to the flexible shaft 20,operation of the switch 320 initiates the advancement, or firingsequence, of the staple driver/cutter 264.

Wireless RCU 148 includes a controller 322, which is electrically andlogically connected with the switches 302, 304, 306, 308 via line 324,with the switches 316, 318 via line 326, with switch 312 via line 328and with switch 320 via line 330. Wireless RCU 148 may includeindicators 18 a′, 18 b′, corresponding to the indicators 18 a, 18 b offront panel 15, and a display device 16′, corresponding to the displaydevice 16 of the front panel 15. If provided, the indicators 18 a′, 18b′ are electrically and logically connected to controller 322 viarespective lines 332, 334, and the display device 16′ is electricallyand logically connected to controller 322 via line 336. Controller 322is electrically and logically connected to a transceiver 338 via line340, and transceiver 338 is electrically and logically connected to areceiver/transmitter 342 via line 344. A power supply, not shown, forexample, a battery, may be provided in wireless RCU 148 to power thesame. Thus, the wireless RCU 148 may be used to control the operation ofthe electro-mechanical surgical device 10 and any surgical instrument orattachment attached to the flexible shaft 20 via wireless link 160.

Wireless RCU 148 may include a switch 346 connected to controller 322via line 348. Operation of switch 346 transmits a data signal to thetransmitter/receiver 146 via wireless link 160. The data signal includesidentification data uniquely identifying the wireless RCU 148. Thisidentification data is used by the controller 122 to preventunauthorized operation of the electromechanical surgical device 10 andto prevent interference with the operation of the electromechanicalsurgical device 10 by another wireless RCU. Each subsequentcommunication between the wireless RCU 148 and the electromechanicaldevice surgical 10 may include the identification data. Thus, thecontroller 122 can discriminate between wireless RCUs and thereby allowonly a single, identifiable wireless RCU 148 to control the operation ofthe electromechanical surgical device 10 and any surgical instrument orattachment attached to the flexible shaft 20.

Based on the positions of the components of the surgical instrument orattachment attached to the flexible shaft 20, as determined inaccordance with the output signals from the encoders 106, 108, thecontroller 122 may selectively enable or disable the functions of theelectromechanical surgical device 10 as defined by the operating programor algorithm corresponding to the attached surgical instrument orattachment. For example, where the surgical instrument or attachment isthe circular surgical stapler attachment 250 illustrated in FIG. 9, thefiring function controlled by the operation of the switch 320 isdisabled unless the space or gap between the anvil 256 and the bodyportion 252 is determined to be within an acceptable range. The space orgap between the anvil 256 and the body portion 252 is determined basedon the output signal from the encoders 106, 108, as more fully describedhereinabove. It should be appreciated that the switch 320 itself remainsoperable but that the controller 122 does not effect the correspondingfunction unless the space or gap is determined to be within theacceptable range.

Referring now to FIG. 12, there is seen a schematic view of a wired RCU150. In the example embodiment, wired RCU 150 includes substantially thesame control elements as the wireless RCU 148 and further description ofsuch elements is omitted. Like elements are noted in FIG. 12 with anaccompanying prime. It should be appreciated that the functions of theelectro-mechanical surgical device 10 and any surgical instrument orattachment attached to the flexible shaft 20 may be controlled by thewired RCU 150 and/or by the wireless RCU 148. In the event of a batteryfailure, for example, in the wireless RCU 148, the wired RCU 150 may beused to control the functions of the electro-mechanical surgical device10 and any surgical instrument or attachment attached to the flexibleshaft 20.

As described hereinabove, the front panel 15 of housing 14 includesdisplay device 16 and indicators 18 a, 18 b. The display device 16 mayinclude an alpha-numeric display device, such as an LCD display device.Display device 16 may also include an audio output device, such as aspeaker, a buzzer, etc. The display device 16 is operated and controlledby controller 122 in accordance with the operating program or algorithmcorresponding to a surgical instrument or attachment, if any, attachedto the flexible shaft 20. If no surgical instrument or attachment is soattached, a default operating program or algorithm may be read orselected by, or transmitted to, controller 122 to thereby control theoperation of the display device 16 as well as the other aspects andfunctions of the electro-mechanical surgical device 10. If the circularsurgical stapler attachment 250 illustrated in FIG. 9 is attached toflexible shaft 20, display device 16 may display, for example, dataindicative of the gap between the anvil 256 and the body portion 252 asdetermined in accordance with the output signal of encoders 106, 108, asmore fully described hereinabove.

Similarly, the indicators 18 a, 18 b are operated and controlled bycontroller 122 in accordance with the operating program or algorithmcorresponding to the surgical instrument or attachment, if any, attachedto the flexible shaft 20. Indicator 18 a and/or indicator 18 b mayinclude an audio output device, such as a speaker, a buzzer, etc.,and/or a visual indicator device, such as an LED, a lamp, a light, etc.If the circular surgical stapler attachment 250 illustrated in FIG. 9 isattached to the flexible shaft 20, indicator 18 a may indicate, forexample, that the electromechanical surgical device 10 is in a power ONstate, and indicator 18 b may, for example, indicate whether the gapbetween the anvil 256 and the body portion 252 is determined to bewithin the acceptable range as more fully described hereinabove. Itshould be appreciated that although only two indicators 18 a, 18 b aredescribed, any number of additional indicators may be provided asnecessary. Additionally, it should be appreciated that although a singledisplay device 16 is described, any number of additional display devicesmay be provided as necessary.

The display device 16′ and indicators 18 a′, 18 b′ of wireless RCU 150and the display device 16″ and indicators 18 a″, 18 b″ of wired RCU 148are similarly operated and controlled by respective controller 322, 322′in accordance with the operating program or algorithm corresponding tothe surgical instrument or attachment, if any, attached to the flexibleshaft 20.

Referring now to FIG. 13, there is seen a flowchart of a main operatingprogram according to the present invention. The main operating programbegins at step 1000 and proceeds to step 1002, during which theelectromechanical surgical device 10 is initialized. Step 1002 mayinclude initialization steps, such as memory population andinitialization, diagnostic self-testing, etc. After initialization step1002, it is determined in step 1004 whether a surgical instrument orattachment (“DLU”) is present—that is, installed on the distal end 24 offlexible shaft 20. If it is determined in step 1004 that no DLU ispresent, control is transferred to loop 1034. If it is determined that aDLU is present, the operating program proceeds to step 1006, in which itis determined whether the FIRE key is pressed. FIRE key, in thiscontext, refers to one of the switches of the wireless RCU 148 and/orwired RCU 150. More particularly, the FIRE key may correspond to switch320 of wireless RCU 148 and/or switch 320′ of wired RCU 150. If it isdetermined in step 1006 that FIRE key is pressed, control is transferredto routine A in step 1008. Routine A is specific to the DLU, if any,attached to the flexible shaft 20. Routine A is more fully describedhereinbelow and in FIGS. 14 a-14 d. After the execution of routine A instep 1008, control is transferred to loop 1034.

If it is determined in step 1006 that the FIRE key is not pressed, it isdetermined in step 1010 whether the CLAMP key is pressed. In thiscontext, the CLAMP key refers to one of the switches of the wireless RCU148 and/or wired RCU 150. More particularly, CLAMP switch may correspondto, for example, switch 316 of wireless RCU 148 and/or to switch 316′ ofwired RCU 150. If it is determined in step 1010 that CLAMP key ispressed, control is transferred to routine B in step 1012. Routine B isspecific to the DLU, if any, attached to the flexible shaft 20. RoutineB is more fully described hereinbelow and in FIGS. 15 a and 15 b. Afterthe execution of routine B in step 1012, control is transferred to loop1034.

If it is determined in step 1010 that the CLAMP key is not pressed, itis determined in step 1014 whether the UNCLAMP key is pressed. In thiscontext, the UNCLAMP key refers to one of the switches of the wirelessRCU 148 and/or wired RCU 150. More particularly, the UNCLAMP switch maycorrespond to, for example, switch 318 of wireless RCU 148 and/or toswitch 318′ of wired RCU 150. If it is determined in step 1014 thatUNCLAMP key is pressed, control is transferred to routine C in step1016. Routine C is specific to the DLU, if any, attached to the flexibleshaft 20. Routine C is more fully described hereinbelow and in FIG. 16.After the execution of routine C in step 1016, control is transferred toloop 1034.

If it is determined in step 1014 that the UNCLAMP key is not pressed, itis determined in step 1018 whether one or more of STEERING keys arepressed. In this context, the STEERING keys refer to respective switchesof the wireless RCU 148 and/or wired RCU 150. More particularly, theSTEERING keys may correspond to switches 302, 304, 306, 308 of wirelessRCU 148 and/or switches 302′, 304′, 306′, 308′ of wired RCU 150. If itis determined in step 1018 that one or more STEERING keys are pressed,operation of respective steering motor(s) is performed in step 1020. Thesteering motors may correspond to third motor 84 and fourth motor 92 asmore fully set forth above. After the execution of step 1020, control istransferred to loop 1034.

If it is determined in step 1018 that none of the STEERING keys ispressed, it is determined in step 1022 whether the DISENGAGE key ispressed. In this context, the DISENGAGE key refers to one of theswitches of wireless RCU 148 and/or wired RCU 150. More particularly,DISENGAGE key may correspond to switch 312 of wireless RCU 148 and/orswitch 312′ of wired RCU 150. If it is determined in step 1022 that theDISENGAGE key is pressed, a disengage operation is performed in step1024. After the execution of step 1024, control is transferred to loop1034.

If it is determined in step 1022 that DISENGAGE key is not pressed, anIDLE routine is performed in step 1026.

In step 1028, it is determined whether to end the operation of the mainoperating program. If it is determined in step 1028 to not end theoperation of the main operating program, control is transferred to loop1034. If, however, it is determined in step 1028 to end or terminate theoperation of the main operating program, a shutdown routine is executedin step 1030, and the main operating program is thereafter terminated instep 1032.

It should be appreciated that the main operating program may determinewhich, if any, key is pressed in the order illustrated in FIG. 13 or inany other appropriate order. It should also be appreciated that the mainoperating program illustrated in FIG. 13, as well as the routinesillustrated in FIGS. 14 a-14 d, 15 a, 15 b and 16, may be embodied, forexample, in a messaging-based, event-driven and/or polling-type softwareapplication.

Referring now to FIGS. 14 a-14 d, there is seen a flowchart of a firingroutine specific to a circular surgical stapler attachment 250, such asthat illustrated in FIG. 9. It should be appreciated that the firingroutine illustrated in FIGS. 14 a-14 d represents the routine A of step1008 of the main operating program illustrated in FIG. 13 and that thefiring routine illustrated in FIGS. 14 a-14 d is specific to a circularsurgical stapler attachment 250, such as that illustrated in FIG. 9. Itshould be further appreciated that other surgical instruments orattachments, such as those enumerated above, may have other firingroutines associated therewith.

Proceeding from step 1008, it is determined in step 1100 whether theDLU—the circular surgical stapler attachment 250—has been fully opened.This determination may be made based on the signals generated by theencoders 106, 108, as more fully described above. If it is determined instep 1100 that the DLU has not been fully opened, an ERROR condition isdetermined in step 1102 in that the DLU is not ready for firing. Controlis then transferred to step 1120, wherein control returns to the mainoperating program illustrated in FIG. 13.

If it is determined in step 1100 that the DLU has been fully opened, itis determined in step 1104 whether the DLU has been fully clamped. Thisdetermination may be made based on the signals generated by the encoders106, 108, as more fully described above. If it is determined in step1104 that the DLU has not been fully clamped, an ERROR condition isdetermined in step 1106 in that the DLU is not within an acceptablerange for firing. Control is then transferred to step 1120, whereincontrol returns to the main operating program illustrated in FIG. 13.

If it is determined in step 1104 that the DLU has been fully clamped, itis determined in step 1108 whether the DLU has been previously fired.This determination may be made based on the signals generated by theencoders 106, 108 and/or in accordance with usage data 184. If it isdetermined in step 1108 that the DLU has been previously fired, an ERRORcondition is determined in step 1110 in that the DLU has been used.Control is then transferred to step 1120, wherein control returns to themain operating program illustrated in FIG. 13. It should be appreciatedthat a similar usage determination may be made in the main operatingprogram illustrated in FIG. 13, for example, in the initialization step1002 or in the DLU presence determining step 1004, as an alternative orin addition to the determining step 1108.

If it is determined in step 1108 that the DLU has not been previouslyfired, a usage count is decremented in step 1112. The usage count may bestored in usage data 184 as more fully described hereinabove. Severalattempts at decrementing the usage count may be made in step 1112.However, a failure to decrement the usage count may nevertheless occur.In step 1114, it is determined whether the usage count decrementing step1112 has failed. If it is determined in step 1114 that the decrementingof usage count failed, a ERROR condition is determined in step 1116.Thereafter, in step 1118, a wait loop is executed until all keys of thewireless RCU 148 and/or wired RCU 150 have been released. After it isdetermined in step 1118 that all keys have been released, control istransferred to step 1120. Thereafter, control returns to the mainoperating program illustrated in FIG. 13.

If it is determined in step 1114 that the usage count decrementing didnot fail, the firing motor current limit is set in step 1122. In thiscontext, the firing motor may correspond to the second motor 80 as morefully described hereinabove. The firing motor is then started in step1124 to begin the advancement of the staple driver/cutter 264.

Referring now to FIG. 14 b, a timer is set in step 1126. It isthereafter determined in step 1128 whether the time elapsed for thefiring operation has exceeded a predetermined threshold. If it isdetermined in step 1128 that the firing time limit has been exceeded,the firing motor is disabled in step 1130, and an ERROR condition isdetermined in step 1132. Control then proceeds to step 1136. If,however, it is determined in step 1128 that the firing time has notexceeded the predetermined firing time limit, it is determined in step1134 whether a hardware current limit has been exceeded. The hardwarecurrent limit relates to the resistance of the firing motor to continuedoperation. A condition that the hardware current limit has been exceededis indicative that the stapling operation has been successfullycompleted. If it is determined in step 1134 that the hardware currentlimit has not been exceeded, the operation of firing motor is continueduntil either the predetermined firing time limit has been exceeded orthe hardware current limit has been exceeded. In either instance controlproceeds thereafter to step 1136.

Step 1136 represents a waiting step, during which a predetermined waittime is permitted to elapse. This wait time permits the driving anddriven elements of electromechanical surgical device 10 and circularsurgical stapler attachment 250 to come to rest before proceeding tostep 1138, in which step the firing motor is stopped.

After the firing motor is stopped in step 1138, the motor current limitis set to full scale in step 1140, and then the firing motor is startedin step 1142 in a reverse direction to retract the staple driver/cutter264 and return the same to its initial position. Then, once the gapbetween the anvil 256 and the body portion 252 has exceeded theacceptable range, the indicator 18 a, 18 b corresponding to an IN-RANGEindicator is turned off in step 1144. Alternatively, the IN-RANGEindicator may be turned off in step 1144 upon the start of the reversalof the motor in step 1142. After the IN-RANGE indicator is turned off instep 1144, the timer is reset in step 1146.

Referring now to FIG. 14 c, it is determined in step 1148 whether apredetermined time limit for completing the retraction of the stapledriver/cutter 264, based on the timer reset in step 1146, has beenexceeded. If it is determined in step 1148 that the predetermined timelimit has been exceeded, an ERROR condition is determined in step 1150in that the retraction operation failed to be completed within thepermissible predetermined time limit. If, however, it is determined instep 1148 that the predetermined time limit has not been exceeded, it isdetermined in step 1152 whether retraction of the staple driver/cutter264 has been completed. If it is determined in step 1152 that theretraction of the staple driver/cutter 264 has not been completed,control returns to step 1148. Retraction of staple driver/cutter 264continues until either the predetermined time limit has been exceeded asdetermined in step 1148 or the retraction has been completed asdetermined in step 1152. It should be appreciated that the determinationmade in step 1152 may be based on the signals generated by the encoders106, 108. After it is determined that the retraction of stapledriver/cutter 264 has been completed (step 1152) or that thepredetermined time limit has been exceeded (step 1148), the unclampmotor current limit is set of full scale in step 1154. In this context,the unclamp motor may correspond to first motor 76 as more fullydescribed hereinabove.

In step 1156, the halfway point between the current position of theanvil 256 and the final, unclamped position of the anvil 256 iscalculated. A “phantom” destination position is set in step 1158 to apredetermined setpoint plus a predetermined bias value to ensure thatthe unclamp motor achieves its maximum, or full, current to therebyensure the maximum torque output from the unclamp motor. In step 1160,the movement of the unclamp motor is initiated. In step 1162, the timeris set, and in step 1164 a destination flag is cleared.

Referring now to FIG. 14 d, it is determined in step 1166 whether theanvil 256 has passed the halfway point determined in step 1156. If it isdetermined in step 1166 that the anvil 256 has passed the halfway pointdetermined in step 1156, the “true” final destination position for theanvil 256 is set in step 1170, thereby superceding the “phantom” finaldestination set in step 1158. Control is then transferred to step 1174.If, however, it is determined in step 1166 that the position of theanvil 256 is not past the halfway point determined in step 1156, controlis directly transferred to step 1174, bypassing the destinationresetting step 1170.

In step 1174, it is determined whether the anvil 256 has reached the“true” final destination set in step 1170. It should be appreciated thatthe position of the anvil 256 may be determined in accordance with thesignals output by encoders 106, 108 as more fully described hereinabove.If it is determined in step 1174 that anvil 256 has reached its “true”final destination set in step 1170, control is transferred to step 1180,described below. If, however, it is determined in step 1174 that the“true” final destination of the anvil 256 has not been reached, it isdetermined in step 1176, with reference to the timer reset in step 1162,whether a predetermined time limit has been exceeded. If it isdetermined in step 1176 that the predetermined time limit has not beenexceeded, control is returned to step 1166, and the unclamp motorcontinues its operation to further unclamp the anvil 256. If, however,it is determined in step 1176 that the predetermined time limit has beenexceeded, and ERROR condition is determined in step 1178 in that theanvil 256 could be moved into its “true” final destination within thepredetermined time limit. Control is thereafter transferred to step1180, in which the steering mechanism is disengaged. In the exampleembodiment of electromechanical surgical device 10 described above, thesteering mechanism may include the fifth motor 96 and/or carriage 100 asmore fully described hereinabove. After the steering mechanism has beendisengaged in step 1180, a wait loop is executed in step 1182 until allkeys of wireless RCU 148 and/or wired RCU 150 have been released. Onceall of the keys have been released, control returns in step 1184 to themain operating program illustrated in FIG. 13.

Referring now to FIGS. 15 a and 15 b, there is seen a flowchart of aclamp routine specific to a circular surgical stapler attachment 250,such as that illustrated in FIG. 9. It should be appreciated that theclamp routine illustrated in FIGS. 15 a and 15 b represents the routineB of step 1012 of the main operating program illustrated in FIG. 13 andthat the clamp routine illustrated in FIGS. 15 a and 15 b is specific toa circular surgical stapler attachment 250, such as that illustrated inFIG. 9. It should be further appreciated that other surgical instrumentsor attachments, such as those enumerated above, may have other clampingroutines associated therewith.

Proceeding from step 1012, it is determined in step 1200 whether a DLUopen flag is set. If it is determined in step 1200 that the DLU openflag is not set, an ERROR condition is determined in step 1202 in thatthe DLU is not ready to clamp. A wait loop is executed thereafter instep 1204, and once all keys of wireless RCU 148 and/or wired RCU 150have been released, control returns in step 1206 to the main operatingprogram illustrated in FIG. 13.

If, however, it is determined in step 1200 that the DLU open flag isset, it is determined in step 1208 whether the gap between the anvil 256and the body portion 252 is greater than a predetermined threshold G₁,such as, for example, 5.0 mm. This determination may be made based onthe signals generated by the encoders 106, 108, as more fully describedabove. If it determined that the gap between the anvil 256 and the bodyportion 252 is less than the predetermined threshold G₁, controlproceeds to step 1220. If, however, it is determined in step 1208 thatthe gap between the anvil 256 and the body portion 252 is greater thanthe predetermined threshold G₁, control proceeds to step 1210 in which aCLAMP motor speed and torque limit are set to the respective maximumvalues. In this context, the CLAMP motor may correspond to first motor76 as more fully described hereinabove. A timer is reset in step 1212,and the control loop of steps 1214 and 1218 is executed until either apredetermined time period for reaching a gap of less than thepredetermined threshold G₁ is exceeded or the gap is determined to beless than the predetermined threshold G₁. If it is determined in step1214 that the predetermined time period has been exceeded, an ERRORcondition is determined in step 1216 in that the clamp operation isconsidered to have failed. After step 1216 is performed, step 1204 isperformed, in which a wait loop is executed until all keys of wirelessRCU 148 and/or wired RCU 150 have been released. Thereafter, controlreturns in step 1206 to the main operating program illustrated in FIG.13.

If it is determined in step 1214 that the predetermined time period hasnot been exceeded, it is determined in step 1218 whether the movement ofthe anvil 256 to a location in which the gap between the anvil 256 andthe body portion 252 is less than the predetermined threshold G₁ hasbeen completed. If it is determined in step 1218 that this move has notbeen completed, the operation of CLAMP motor is continued, and controlreturns to step 1214. If however, it is determined in step 1218 that themove is complete, control proceeds to step 1220.

In step 1220, a speed lower than the maximum speed set in step 1210 isset for the CLAMP motor and a torque limit lower than the torque limitset in step 1210 is set for the CLAMP motor. Thereafter, in step 1222, aposition bias is set to ensure that the CLAMP motor outputs full torquewhen the gap between the anvil 256 and the body portion 252 approachesthe bias value. The bias value may be, for example, approximately 1.0 mmto ensure full torque output from the CLAMP motor when the gap isapproximately equal to 1.0 mm.

Referring now to FIG. 15 b, control proceeds to step 1224, in which atimer is reset. In step 1226, the value of the current gap between theanvil 256 and the body portion 252 is displayed on the display device16. In step 1228, it is determined whether the gap between the anvil 256and the body portion 252 is less than a predetermined threshold G₂. Thisdetermination may be made based on the signals generated by the encoders106, 108, as more fully described above. The predetermined threshold G₂may be, for example, 2.0 mm. If the gap between the anvil 256 and thebody portion 252 is determined in step 1228 to be less than thepredetermined threshold G₂, control proceeds to step 1230, in which anIN-RANGE indicator is activated and a DLU ready flag is set. TheIN-RANGE indicator may correspond to one of the indicators 18 a, 18 b,either one or both of which may be, for example, LED elements or otheraudio or visual indicators. If it is determined in step 1228 that thegap between the anvil 256 and the body portion 252 is not less than thepredetermined threshold G₂, control proceeds to step 1232, in which itis determined whether the gap between the anvil 256 and the body portionis less than or equal to another predetermined threshold G₃. Thisdetermination may be made based on the signals generated by the encoders106, 108, as more fully described above. The predetermined threshold G₃may be, for example, 1.0 mm. If it is determined in step 1232 that thegap between the anvil 256 and the body portion 252 is less than or equalto the predetermined threshold G₃, control proceeds to step 1238,described below. However, if it is determined in step 1232 that the gapbetween the anvil 256 and the body portion 252 is greater than thepredetermined threshold G₃, it is determined in step 1234 whether thecurrent limit to the CLAMP motor has been reached for a predeterminedtime limit. That the current limit to the CLAMP motor has been reachedfor the predetermined time limit is indicative that tissue is fullyclamped between the anvil 256 and the body portion 252. Thepredetermined time limit may be, for example, 1.0 second. If it isdetermined in step 1234 that the current limit to the CLAMP motor hasbeen reached for the predetermined time limit, control proceeds to step1238. If, however, it is determined in step 1234 that the current limitto the CLAMP motor has not been exceeded for the predetermined timelimit, it is determined in step 1236 whether the CLAMP key has beenreleased. If it is determined in step 1236 that the CLAMP key has notbeen released, control returns to step 1226. If it is determined in step1236 that the CLAMP key has been released, control proceeds to step1238.

In step 1238, the operation of the CLAMP motor is stopped. Thereafter,in step 1240, a wait loop is executed until all keys of wireless RCU 148and/or wired RCU 150 have been released. After all keys have beenreleased, control returns in step 1242 to the main operating programillustrated in FIG. 13.

Referring now to FIG. 16, there is seen a flowchart of an unclamproutine specific to a circular surgical stapler attachment 250, such asthat illustrated in FIG. 9. It should be appreciated that the unclamproutine illustrated in FIG. 16 represents the routine C of step 1016 ofthe main operating program illustrated in FIG. 13 and that the unclamproutine illustrated in FIG. 16 is specific to a circular surgicalstapler attachment 250, such as that illustrated in FIG. 9. It should befurther appreciated that other surgical instruments or attachments, suchas those enumerated above, may have other unclamp routines associatedtherewith.

Proceeding from step 1016, a torque limit for an UNCLAMP motor is set instep 1300 to its maximum value. The UNCLAMP motor may correspond to theCLAMP motor as more fully described hereinabove. The UNCLAMP motor mayalso correspond to the first motor 76 as more fully describedhereinabove.

In step 1302, the destination position for the anvil 256 is set to avalue representative of its fully unclamped position. The operation ofthe UNCLAMP motor is initiated in step 1304. In step 1306, it isdetermined whether the UNCLAMP key has been released. If it isdetermined in step 1306 that the UNCLAMP key has been released, controlproceeds to step 1314. If it is determined in step 1306 that the UNCLAMPkey has not been released, it is determined in step 1308 whether the gapbetween the anvil 256 and the body portion 252 is greater than or equalto a predetermined threshold G₄, which is defined in accordance with thedestination position set in step 1302. This determination may be madebased on the signals generated by the encoders 106, 108, as more fullydescribed above. If it is determined in step 1308 that the gap betweenthe anvil 256 and the body portion 252 is greater than or equal to thepredetermined threshold G₄, a DLU opened flag is set in step 1310.Control then proceeds to step 1312. If it is determined in step 1308that the gap between the anvil 256 and the body portion 252 is less thanthe predetermined threshold G₄, it is determined in step 1312 whetherthe unclamp operation is complete. That is, whether the destinationposition for the anvil 256 set in step 1302 has been reached. If it isdetermined in step 1312 that the movement of the anvil 256 is notcomplete, control returns to step 1306. If it is determined in step 1312that the movement of the anvil 256 is complete, the operation of theUNCLAMP motor is stopped in step 1314. Control then returns in step 1316to the main operating program illustrated in FIG. 13.

It should be understood that the operation of the several motors andswitch elements as described above with respect to the circular surgicalstapler attachment 250 are specific to the circular surgical staplerattachment 250. The motor(s) and/or switch(es) may perform otherfunctions when other surgical instruments or attachments are attached toflexible shaft 20.

Thus, the several aforementioned objects and advantages of the presentinvention are most effectively attained. Those skilled in the art willappreciate that numerous modifications of the exemplary embodimentdescribed hereinabove may be made without departing from the spirit andscope of the invention. Although a single exemplary embodiment of thepresent invention has been described and disclosed in detail herein, itshould be understood that this invention is in no sense limited therebyand that its scope is to be determined by that of the appended claims.

1. A surgical instrument for use with an electro-mechanical surgicaldevice, comprising: a coupling provided at a proximal end of thesurgical instrument and configured to couple the surgical instrumentwith the electro-mechanical surgical device; a memory unit provided inthe surgical instrument; and at least one rotatable drive shaft providedin the surgical instrument and configured to couple, via the couplingprovided at the proximal end of the surgical instrument, with arespective drive shaft of the electro-mechanical surgical device;wherein the coupling provided at the proximal end of the surgicalinstrument includes a data connector configured to connect the memoryunit provided in the surgical instrument with the electro-mechanicalsurgical device; and wherein the at least one rotatable drive shaftincludes a first rotatable drive shaft and a second rotatable driveshaft, each of the drive shafts being (i) configured to couple with arespective drive shaft of the electro-mechanical surgical device, (ii)driven independently by a different motor, and (iii) configured toinclude a magnet mounted thereon for producing a magnetic field and inoperable communication with at least one encoder including at least twosensors disposed approximately 90° apart relative to a longitudinal axisof each of the drive shafts, an output of the at least two sensorsadapted to be adjusted as a function of a change of polarity of themagnetic field in a detection range of the at least two sensors, and apair of additional motors secured on a carriage which carriage ismovable to permit selective engagement of a selected one of the pair ofadditional motors, wherein the pair of additional motors control asteering of the surgical instrument.
 2. The surgical instrumentaccording to claim 1, wherein the memory unit is configured to store atleast one of a first data corresponding to a type of the surgicalinstrument and a second data representing a usage of the surgicalinstrument.
 3. The surgical instrument according to claim 2, wherein theat least one of the first data and the second data is readable by acontrol system of the electro-mechanical surgical device.
 4. Thesurgical instrument according to claim 1, wherein the data connector isconfigured to electrically and logically connect the memory unit to acontrol system of the electro-mechanical surgical device.
 5. Thesurgical instrument according to claim 1, wherein the coupling isconfigured to detachably attach the surgical instrument to theelectro-mechanical surgical device.
 6. The surgical instrument accordingto claim 1, wherein the surgical instrument includes a surgicalstapler/cutter instrument.
 7. The surgical instrument according to claim6, wherein the surgical stapler/cutter instrument includes an anvilportion and a staple driver/cutter portion.
 8. The surgical instrumentaccording to claim 7, wherein the first rotatable drive shaft'sconfigured to open and close the anvil portion and a the secondrotatable drive shaft configured to drive the staple driver/cutterportion.